Precision imaging systems, such as RADARs (radio detection and ranging), LIDARs (light detection and ranging), etc., are generally mounted on gimbals so that the detection device will remain suspended in a plane regardless of any motion of a vehicle on which the device sits. This allows the detection device to produce high resolution imagery that is not distorted due to the vehicle movements or accelerations.
In addition, the detection device usually requires accurate velocity data of the detection device for image stabilization purposes. Thus, such radar or lidar systems will have inertial sensors like gyroscopes and accelerometers mounted within the imaging system's gimbal assembly and next to the detection device of the imaging system to provide vehicle position and velocity data in the gimbal frame of reference. While this solves the need of the imaging system for accurate attitude data (e.g., position of aircraft or vehicle relative to a frame of reference—the horizon or direction of motion), velocity and position data at the detection device, this data does not reflect the actual vehicle attitude, velocity, or position since the inertial sensors are mounted on the gimbal. As a result, the vehicle typically has another set of accelerometers and gyroscopes that provide attitude, velocity and position data of the vehicle.
Of course, two sets of inertial sensors increases costs and complexity for imaging systems. It would be desirable to eliminate the need for a separate set of inertial sensors that provide vehicle attitude, angular rate data, velocity and position, and to acquire this data from the sensors mounted on the gimbal assembly.